7.beta.-[.alpha.-(2-amino-5-halo-4-thiazolyl)-.alpha.-alkoxyiminoacetamido] -cephalosporins have been disclosed in Japanese published patent application No. 52195/1976 (TAKEDA) excluding 3-unsubstituted cephem compounds. A description was also made in Japanese published patent application No. 149,296/1976 (TAKEDA) on cephem and penam compounds having an .alpha.-(2-amino-5-halo-4-thiazolyl)-.alpha.-alkoxyiminoacetamido group as a side chain, but no specific disclosure has been found on a 3-unsubstituted-3-cephem-4-carboxylic acid nucleus. Further, this paper mentioned no bactericidal activity of the compounds. Japanese published patent application No. 13,0691/1978 (HOECHST) discloses .alpha.-(2-amino-5-unsubstituted-4-thiazolyl)-.alpha.-alkoxyiminoacetamido -3-unsubstituted-3-cephem compounds in their scope but failed to support 3-unsubstituted-3-cephem nucleus with scientific data, in spite of detailed disclosure on other types of cephem nuclei.
Now, high antibacterial activity has been found on Compounds (I) having high antipseudomonal activity over non-halogenaged thiazolyl derivatives and 3-alkyl, 3-halo, 3-acyloxymethyl, and 3-heterothiomethyl derivatives as is disclosed later. Thus, the present inventors declare their invention.
After priority date of this application, Japanese published patent application No. 52,096/1979 (FUJISAWA) was published covering Compounds (I) carrying no halogen at the 5-position off thiazole ring. This compound has been used as standard in our priority application.